Electrical transformer.



Patented SeptlO, l90l. A. F. BERRY.

ELECTRICAL TRANSFORMER.

A n filed Jan. 23, 1901.)

IILII eissea No. 682,520. Patented Sept. l0, l90l. A. F. BERRY.ELECTRICAL TBANSFOBIER.

(Applicltion 11104 Jul. 28, 1901.)

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No. 682,520. Patented Sept. l0, l90l. A. F. BERRY.

ELECTRICAL TRANSFORIEB.

(Applicltion am 1;. as, 190:. (Ila Ilodol.) 5 Shoots-Shut 4.

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Witnesses, 5 Jill/en [or No. 682,520. I Patented Sept. I0, 190i. A. F.BERRY.

ELECTRICAL TRANSFORMER (Appliclficm fllld JUL 93, 1901.) (lo Iodel.) 5Shoots-Sheet 5.

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' the block shown in Fig. 3.

UNITED STATES PATENT OEEIcE.

ARTHUR FRANCIS BERRY, OF LONDON, ENGLAND.

ELECTRICAL TRANSFORMER.

SPECIFICATION forming part of Letters Patent No. 682,520, dated.September 10, 1901.

Application filed January 23, 1901. Serial No. 44,429. tNo'model.)

To all wit/017v it nuty concern;

Be it known that I, ARTHUR FRANCIS BERRY, a subject of the Queen ofGreat Britain and Ireland, residing at Harrow road, London, England,have invented Improvements in Electrical Transformers, of which thefollowing is a specification.

This invention has reference to further improvements in electricaltransformers of the type described in the specification of formerLetters Patent granted to meviz., No. 639,505; and it has for objects tofacilitate the construction and lessen the cost of such transformers, toadapt the same for the generation of diphase or polypbase currents, andto provide for the efficient cooling of the windings of suchtransformers.

It consists for these purposes in an improved construction of thecentral portion of the iron core that passes through the primary andsecondarywindings of the transformer, in an improved construction of thelaminated plates, so as to provide two or more circuits for magneticflux, in an improved construction of one or some of the windings, so asto provide for the cooling thereof, and in certain details ofconstruction, all as hereinafter more fullydescribed, and pointed out inthe claims.

In the accompanying illustrative drawings, Figure 1 shows partly in sideelevation and partly in vertical section on the line A A of Fig. 2, andFig. 2 in horizontal section on the line B B of Fig. 1, one constructionof electrical transformer embodying my present invention. Fig. 3 showsin plan and to a larger scale than Figs. 1 and 2 a differentconstruction of one of the laminated sector-shaped blocks for formingthe central portion of the transformer-core. Figs. 4 and 5 areelevations taken at right angles to one another of Figs. 6, 7, and 8 aresimilar views to Fig. 3, showing modified constructions of sector-shapedblocks. Fig.

9 is a part side elevation, and Fig. 10 a part plan, showing a modifiedway of building up the sector-shaped blocks. Fig. 11 shows in plananother construction of sector-shaped block. Fig. 12 is a plan showingvarious ways in which the groups of iron strips constituting the top,bottom, and'outside members of the laminated plates forming thetransformer-core can be arranged.

a and Z), Figs. 1 and 2, are, respectively the inner and outer sides orlegs, and c and d the top and bottom members, of the laminatedoutwardly-extending iron plates forming the core, through which theprimary and secondary windingsp and g, respectively, extend in a mannerwell understood and as described in my said former specification, eachvertical side or leg and each top and bottom member being composed ofstraight strips of thin sheet-iron, as before. According to thisinvention the vertical straight strips of thin sheet-iron constitutingthe inner sides or legs a of the laminated iron plates at b c dare madeof different widths, such that when the strips are placed adjacent toeach other around a common center they form, as seen in plan,sector-shapedor approximately sector-shaped blocks or bundles of ironstrips, the widest strip or strips in each block or bundle extending toor nearly to the center of the core, and the strips on one or each sideof the widest strip or strips being of successively less width, thearrangement, moreover, being such that passages are or may be leftbetween the adjacent sides or some of them, and it may be between theinner ends of the several sector-shaped blocks or bundles of strips,(hereinafter called blocks (1,) which are arranged to constitute thecentral portion of the core that extends through the primary andsecondary coils.

In Figs. 1 and 2 each of the sector-shaped blocks Ct is composed of anumber of straight strips of iron, the central one of which is thewidestand those on each side of the central one are of successivelylesswidth, the block being made of such dimensions as to leave verticalspaces or channels 6 between its sides and the sides of the adjacentsector-shaped blocks a. The strips of iron composing each block are forthe sake of clearness shown as simple lines separated from each other;but they would of course in actual construction be placed close againsteach other.

In practice each block a preferably comprises, as shown in Figs. 3 to10, inclusive, a central group of vertical straight strips of ironhaving the greatest width, and on each side of such central group anumber of other groups of vertical strips of iron of successively lesswidth, but with the strips in each group of the same width,'so that thesides of .I so

the resulting sector-shaped block composed of the several groups ofstrips have a steplike shape and when placed adjacent tosimilarly-shaped blocks of iron strips to constitute the central portionof the core, as shown in Figs. 3,6,,and 10,forn1 with such other blocksa number of, vertical four-sided Ventilating or cooling holes orpassages f, a vertical ventilating or cooling hole or passage g ofpolygonal shape being also formed by and between the inner ends of thecentral groups of strips in the several blocks.

The iron strips comprising each sectorshaped block a are or'mayadvantageously be secured together in any suitable manner, so that thesaid block of strips constitutes practically one piece that can beeasily handied and arranged to form with the remaining similarly-shapedblocks at the central portion of the transformer-core. For this purposethe said strips may, forexample, be secured together by bolts 71,,Figsl'3, 4, and 5, that pass transversely through them at points belowand above their junction with the top and bottom members 0 and d,respectively, of the rectangular laminated iron plate of which they formthe inner side or leg, the said bolts, if of conducting material, beingcovered with a sleeve h, of non-conducting and non-magnetic material, orthe strips may be held together by a correspondingly-shaped holder e',Fig. 6, of suitable sheet material, the outer ends of which may besecured to the block a by insulated bolts h. A layerj of suitableinsulating material may be socured over the outer vertical surface ofthe block by the bolts h, or the strips compos ing each block a may becaused to adhere one to another by suitable means, such as by coatingthem with shellac varnish and after putting them together heating themin an oven to a temperature sufficient to. expel the spirit,

so that in each case the strips are effectually held together.

' -The several groups of strips constituting each block a may, asshownin Fig. 7, be separated from one another by layers k of nonmagneticmaterial, which may be insulating or not, or, as shown in Fig. 8, byair-spaces Z,

formed by placing strips m of non-magnetic material between the groupsof strips in order in each case to prevent magnetic flux leaking fromone group of strips to another.

Instead of binding the strips of iron in each block a together, so thatthey can be handled as one article, as in Figs. 2 to 6, inclusive,

the several groups of iron strips of difierent width constituting eachblock a may be forced into position between stepped plates that aresuitably held in position. For this purpose two plates may, as shown inFigs. 9 and 10, be held between top'and bottom plates 0 and d and havetheir adjacent inner ends n fixed in a slotted centrally-arranged pillar1", their outer ends being each provided with upper and lower projectingparts 8 s, that are bent themviz., s-will bear against the block a,

embraced by the said plates 70, and the others or otherviz., s-will bearagainst the adjacent block a, the several parts .9 and 8 beingmaintained in the position shown by intermediate rods t, which are heldin place by the plates 0 and (Z. By these means the several plates 70 7care rigidly interconnected and held firmly in position during theinsertion between them of the strips of iron to form the blocks a.

The strips of iron in each sector-shaped block a instead of beingarranged and connected together to form one block having stepped sidesmay, as shown in Fig. 11, be arranged to form two blocks, the adjacentsurfaces a' of which are plane and the outer surfaces of which arestepped.

By the construction hereinbefore described not only can the centralportion of the transform er-core be more readily built up thanheretofore, butthe desired section of iron to form the central portionof the core of a transformer for any required output can be arrangedwithin a circle of smaller diameter than heretofore, with the resultthat the primary and secondary windings p and q, Figs. 1 and 2, andtransformer-core for any given transformer can be made of smaller diameprevious constructions of transformers.

The strips of iron in each sector-shaped block a are arranged, as shownin Figs. 1, 4, and 5, so that the ends of alternate strips projectbeyond oroverlap theintermediate strips and form spaces to, into whichthe similarlyprojecting or overlapping ends of the iron strips formingthe top and bottom members a and d of the corresponding laminated ironplate project, so as to form butt and lap joints ter, and therefore ofless cost, than with my ICC therewith, as in the construction of transformer-core described in my said former specification.

The strips of iron forming the top and bot- I tom members c'and d andthe outer side or leg b of each laminated iron plate may be variouslyarranged, Thus the, strips to form the top member and also those to formthe bottom member may be arranged close together, so as to form'onegroup or b-undleof strips, as shown at 1 in Fig. 12, or they may bearranged in several groups corresponding, itmay be, to the severalgroups composing the corresponding inner side or leg to which they arejointed and arranged to slightly diverge from each other, as shown at win Fig. 12. The strips of iron forming the outer side or leg I) of eachlaminated plate may be arranged to form, as seen'in plan, either asector or approximately sector shaped block, like the inner side or legat of the laminated plate and as shown at 02' in Fig. 12, or arectangular-shaped block, when the strips constituting the top member 0of the plate form a single group or bundle, as shown at 'v in Fig. 12and in Fig. 2, and those constituting the bottom member dalso form asingle group or bundle, or the said strips may be arranged to formseveral blocks or bundles each of rectangular shape in plan, when thestrips in the top and bottom members a and d are arranged in severalgroups, as shown at w in Fig. 12. The ratio between the sectional areasof the corresponding groups of strips in the inner and outer sides orlegs of each plate should be maintained as nearly equal as possiblethroughout the several groups of strips in each laminated plate in orderto prevent magnetic flux passing sidewise from one group of strips tothe next adjacent group bers 1, each composed of straight strips ofiron, so that each plate thus formed has three complete magneticcircuits around the three sets of primary and secondary coils p and g,which extend through the plates, the transformer being thus adapted fortransforming triphase currents. For transforming diphase currents onlyone intermediate member 1 and two sets of windings would be used. Byusing more than two intermediate members 1 and more than three sets ofwindings the transformer will be adapted for use with electric systemsinvolving any requisite number of phases greater than triphase. It willbe seen thatin each case the transverse member 1, or each such member,forms part of and is common to two adjacent magnetic circuits, so that asmall amount of iron can be used and the transformer made compact. Thisis rendered possible by the fact that the magnetic flux set up in thetwo circuits, of which the said intermediate member forms a part,attains the maximum amount at difierent times in the two circuits. Intransformers of the type herein referred to and others in which theprimary and secondary windings are arranged one inside the other andextend through laminated plates or frames the heat generated in the massof the windings, especially in the case of large transformers and whenone winding is arranged between and in close contact with two otherwindings, cannot, with the constructions heretofore usually adopted,readily pass away, with the result that the insulation may be injuredand the efiiciency of the transformer reduced. To obviate this drawback,the windings have sometimes been made of such relative diameters as toleave a complete air-space between them; but this arrangement has thedisadvantage that it reduces the eflicient regula tion of thetransformer. T0 obviate all the foregoing disadvantages, one or more oreach winding is at parts thereof that project beyond the laminated ironplates surrounding them bent away from the adjacent winding, so as toform Ventilating or cooling passages that extend between the twoadjacent windings in a direction at right angles to the direction ofwinding and through which air or other cooling medium can be caused topass, so as to carry oif heat and keep the interior of the combinedwindings cool, and this without interfering with the eificientregulation of the transformer. In Fig. 2 each of the two secondarywindings q, arranged at the inner and outer peripheries of the centralprimary winding p, is at the parts between the laminated core-platesmade with bends 2, that extend away from the primary coil p, so as toform therewith vertical air-passages 3, which extend at right angles tothe plane of the windings and which will allow of air flowing betweenthe adjacent primary and secondary windings and carrying off heat fromthe interior of the combined windings. As will be seen, by arranging thebends 2 between the laminated core-plates they will not interfere withthe windings being brought as close together as possible at the activepartsviz., where the laminated plates surround them so that theformation of the air-passages 3 will not materially interfere with theefficient regulation of the transformer.

My improved transformer may be built up substantially in the mannerdescribed in my said former specification; but in the present case thecentral cylindrical former or mandrel previously used for supporting thevertical strips to form the central portion of the transformer-core isdispensed with, the several sector-shaped blocks a to form the centralportion of the said core being simply arranged around a common center inclose proximity to one another and being held between two end plates orsupports, one of which holds the strips of iron to form the bottommembers of the core-plates during the building up of the transformer.

What I claim is 1. As a new article of manufacture, a laminated ironblock made of sector or approximately sector shape in cross section andadapted to form part of a transformer-core, said block being composed ofa number of parallel strips of sheet-iron made of different widths andheld firmly together, substantially as described.

2. As a new article of manufacture, a laminated iron block adapted toform part of a transformer-core and composed of strips of sheet-iron ofdifferent widths held firmly against each other with the widest strip orstrips in the center and with the strips on each side of such wideststrip or strips of successively less width, substantially as described.

3. As a new article of manufacture, a laminated iron block adapted toform part of a transformer core and'co'mposed of groups of 'strips'ofsheet-iron placed side by side and -'transforiner-core and composed ofst'ripsof I sheet-iron, said block comprising a central group of strips'of iron having the greater widthand on each side thereof a'numb'er ofother groups of strips of iron of successively less width but witht hestrips in each group of thesamewidth, substantiallyasdescribed.

5. As a newarticle of manufacture, a laminated iron block adapted toform part of a. transformer-core and composed of groups of strips ofsheet-iron placed side by- 's'i de and heldtogether, the groups being ofdiiiere'nt widths with the strips in :each group of the same width andwith' a layer-of non-magnetic material between adjacent groups.

6. As a new article of man-u'facture alaminated iron block adapted toform p'artof a; transformer --core and composed" of long straightparallel strips of sheet-iron =of di'ifer- I ent widths held sideby'side with the ends of alternate strips arranged to overlap thecorresponding ends of the intermediate strip's.

7. As a'new'ar ticle of manufacture, a laminated iron block adapted 'tofo'rm partof a' "transformer-core and composed'of groups "of i straightparallel strips "of sheetiron, the

widest group or groups being arranged centrally withthe groups on eachside thereof of successively less width, the strips in eachgroup beingofthe same width,-and the ends of alternate strips being arranged tooverlap 1 thc corresponding ends of the intermediate 1 tweentheiradjacent sides and betweenfitheir strips.

8. In -an=electrical 'transformeig the combination with the primaryandsecondary windings, of a laminated iron 'corethecerrtralpoc 'tion ofwhich, extending through thecente'r of said windings is composed ofstrips of-sheettion of which, extending through the center of saidwindings, is composed of strips of sheet-iron arranged in sets, each setbeing composed of strips of different widths arranged side by side, thewidest strips being arranged at the center of the set and the strips oneach side of the widest being of successively less width-so as to form asector or approximately sector shaped setof strips.

10. Inan electrical transformer, the combination with the primary andsecondary windings, of a laminated iron core the central portion ofwhich, extending through the ecu-- ter of said windings, is composed ofstrips of sheet-iron arranged in sets, each set being composed of groupsof strips ofdiiierent eea sao widths with the strips "in each group ofthe same width.

11. In an electrical transformer, 'the combination with the primaryand'secondary'windings, of a laminated ironcore'the central portion ofwhich, extending through the center of said windings, is composed ofstrips of sheet-iron arranged in sets, each set being composed of groupsof strips of difierent widths with the strips 'ine'achg'group of the 1same width, the widest grou'p-or groups being arranged at the center ofthe set and the groups of 'successivelyi-less width being arranged atthe opposite sides of the center group or groups, substantially asdescribed.

12. Ina'n electricaltransformer, the combination fwiththezprima'ryand'sec'ondary windings, of a laminated iron coresurrounding the 'said windings, :and the central portion of whi'chextends through the windings and is com osed of a number of sector-likeblocks orbu-n'dles of strips of iron, the strips i neach block or bundlebeing arranged in groups of difi eren t widths, arranged side by side,"and each composed of strips of the same width,

substantially as described.

luau-electrical transformer,theaco'mbh nationw'ith the primaryandseconda'ry windings,-'of'alaminated iron core-surrounding the saidwindings, and the central portion of which extends through "the windingsand is composed of la n'u m'b'er "of secto'r-l'i'ke blocks arrangedaround a common center and each "composed of a central group of strips"of iron,

and onea'ch side the'reofla nu-m'b'erof groups p of strips of iron ofsuccessively less width,

the :strips of iron in each group beingof the same width, thesaid blocksbeing arranged so that holes or passages will be fo'rme'd beinner ends,substantially as described.

14:. J nan-electrical transformer, the'combination with ithe pri'maryand rse'condary windings, of a laminated iron core encircling s'aidwindings and *compr-isin'g'a central :portion "composed of straightstrips of sheet-iron extending through the center -'of the windings Yand arranged to form a njumber of sector-like sets o'f strips that arearranged side by' side and 'are of difierent widths, and top, bottom:andouter vertical sets :of straight strips that are interlockedwith'each other and with the central sets of 'strips, substantially asdescribed.

15. In an electrical transformer, 'a transformer -core comprising anumber of iron plates extending radially from the central portion ofthecore-and each comprisi-n g laminated inner, outer, top-and bottommembers with one "or more laminated intermediate separately surroundingeach set of windings so as to form an independent magnetic circuit forsuch set of windings.

17. An electric transformer comprising two or more sets of primary andsecondary windings, a core built up of strips of iron arranged to formlaminated plates extending radially from a center and surrounding eachof said sets of windings and forming twoor more magnetic circuitstherefor.

18. An electric transformer comprising an iron core composed of ironplates extending radially from the central portion of said core and eachcomprising laminated inner, outer, top and bottom members with one ormore laminated intermediate horizontal members, said members beingarranged to form two or more openings through each plate, and primaryand secondary windings extending through each of said openings,substantially as described for the purpose specified.

19. An electric transformerhaving primary and secondary windingsarranged one inside the other and one of which is formed at intervalswith bends arranged to form with the adjacent winding, a number ofair-passages that extend in a direction at right angles to the plane ofthe windings, substantially as described for the purpose specified.

20. An electric transformerhaving primary and secondary windingsarranged one inside the other and one of which is arranged between theothers, the outer windings being each bent away from the center windingat intervals so as to form between the adjacent windings a number ofair-passages that extend in a direction at right angles to the plane ofwinding, substantially as described.

21. An electric transformer having concentrically arranged primary andsecondary windings the winding on each side of the center one being ofcorrugated shape and arranged to bear against said center winding atintervals so as to form therewith a number of air-passages that areparallel to the axis of the windings, substantially as described.

22. An electric transformer comprising concentrically-arranged primaryand secondary windings composed of an outer winding, an intermediatewinding and an inner winding, and laminated iron plates surrounding saidwindings, theinner winding at points between said plates being bent awayfrom said intermediate windin g, substantially as described.

23. An electric transformer comprising con centrically-arranged primaryand secondary windings composed of an outer winding, an intermediatewinding and an inner winding, and laminated iron plates surrounding saidwindings, the outer winding at points between said plates being bentaway from said intermediate winding, substantially as described.

24. An electric transformer comprising concentrically-arranged primaryand secondary windings composed of an outer winding, an intermediatewinding and an inner winding, and laminated iron plates surrounding saidwindings, the inner and outer windings being each bent away from saidintermediate windings at points between said plates so as to formair-passages with said intermediate winding at its inner and outersurfaces, substantially as described for the purpose specified.

Signed at 7'7 Oornhill, in the city of London, England, this 2d day ofJanuary, 1901.

ARTHUR FRANCIS BERRY. lVitnesses:

VVM. 0. BROWN, PERCY E. MATTOOKS.

